Микропроцессорные средства и системы (стр. 3 из 4)
 |
Карта памяти :
| 3FFh | 7FFh | BFFh | FFFh | ||
| 0000h | ROM 1 | RAM 1 | - | 0FFFh | |
| 1000h | - | 1FFFh | |||
| 2000h | IN-OUT 1 | 2FFFh | |||
| 3000h | ROM 2 | 3FFFh | |||
| 4000h | 4FFFh | ||||
| 5000h | RAM 2 | 5FFFh | |||
| 6000h | 6FFFh | ||||
| 7000h | - | 7FFFh | |||
| 8000h | IN-OUT 2 | 8FFFh | |||
| 9000h | 9FFFh | ||||
| A000h | AFFFh | ||||
| B000h | BFFFh | ||||
| C000h | CFFFh | ||||
| D000h | DFFFh | ||||
| E000h | EFFFh | ||||
| F000h | FFFFh | ||||
| 000h | 400h | 800h | C00h | ||
Задача № 3
Разделить адресное пространство 64 килобайта на 18 равных частей. В качестве дешифратора адреса используется ПЛМ. Разбиение адресного пространства показать в виде схемы и таблицы.
Размер одной части 65536 / 18 = 3640 байт. Т.к. 3640 * 18 = 65520, последние 16 ячеек не будут использоваться.
Произведем разбиение 3640 байт на участки 2N :
3640 = 2048 + 1024 + 512 + 32 + 16 + 8
В результате получим 6 областей памяти по 18 участков в каждой :
0000h-8FFFh ( участки размером 2048 )
9000h-D7FFh ( участки размером 1024 )
D800h-FBFFh ( участки размером 512 )
FC00h-FE3Fh ( участки размером 32 )
FE40h-FF5Fh ( участки размером 16 )
FF60h-FFEFh ( участки размером 8 )
Прошивка ПЛМ 1
| Область | Диапазон адресов | Разряды адреса | |||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | ||
| 1 | 0000h-07FFh | 0 | 0 | 0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X |
| 9000h-93FFh | 1 | 0 | 0 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | |
| D800h-D9FFh | 1 | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | |
| FC00h-FC1Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | X | X | X | X | X | |
| FE40h-FE4Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | X | X | X | X | |
| FF60h-FF67h | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | |
| 2 | 0800h-0FFFh | 0 | 0 | 0 | 0 | 1 | X | X | X | X | X | X | X | X | X | X | X |
| 9400h-97FFh | 1 | 0 | 0 | 1 | 0 | 1 | X | X | X | X | X | X | X | X | X | X | |
| DA00h-DBFFh | 1 | 1 | 0 | 1 | 1 | 0 | 1 | X | X | X | X | X | X | X | X | X | |
| FC20h-FC3Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | X | X | X | X | X | |
| FE50h-FE5Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | X | X | X | X | |
| FF68h-FF6Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | X | X | X | |
| 3 | 1000h-17FFh | 0 | 0 | 0 | 1 | 0 | X | X | X | X | X | X | X | X | X | X | X |
| 9800h-9BFFh | 1 | 0 | 0 | 1 | 1 | 0 | X | X | X | X | X | X | X | X | X | X | |
| DC00h-DDFFh | 1 | 1 | 0 | 1 | 1 | 1 | 0 | X | X | X | X | X | X | X | X | X | |
| FC40h-FC5Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | X | X | X | X | X | |
| FE60h-FE6Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | X | X | X | X | |
| FF70h-FF77h | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | X | X | X | |
| 4 | 1800h-1FFFh | 0 | 0 | 0 | 1 | 1 | X | X | X | X | X | X | X | X | X | X | X |
| 9C00h-9FFFh | 1 | 0 | 0 | 1 | 1 | 1 | X | X | X | X | X | X | X | X | X | X | |
| DE00h-DFFFh | 1 | 1 | 0 | 1 | 1 | 1 | 1 | X | X | X | X | X | X | X | X | X | |
| FC60h-FC7Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | X | X | X | X | X | |
| FE70h-FE7Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | X | X | X | X | |
| FF78h-FF7Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | |
| 5 | 2000h-27FFh | 0 | 0 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X |
| A000h-A3FFh | 1 | 0 | 1 | 0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | |
| E000h-E1FFh | 1 | 1 | 1 | 0 | 0 | 1 | 0 | X | X | X | X | X | X | X | X | X | |
| FC80h-FC9Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | X | X | X | X | X | |
| FE80h-FE8Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | X | X | X | X | |
| FF80h-FF87h | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | X | X | X | |
| 6 | 2800h-2FFFh | 0 | 0 | 1 | 0 | 1 | X | X | X | X | X | X | X | X | X | X | X |
| A400h-A7FFh | 1 | 0 | 1 | 0 | 0 | 1 | X | X | X | X | X | X | X | X | X | X | |
| E200h-E3FFh | 1 | 1 | 1 | 0 | 0 | 0 | 1 | X | X | X | X | X | X | X | X | X | |
| FCA0h-FCBFh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | X | X | X | X | X | |
| FE90h-FE9Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | X | X | X | X | |
| FF88h-FF8Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | X | X | X | |
| 7 | 3000h-37FFh | 0 | 0 | 1 | 1 | 0 | X | X | X | X | X | X | X | X | X | X | X |
| A800h-ABFFh | 1 | 0 | 1 | 0 | 1 | 0 | X | X | X | X | X | X | X | X | X | X | |
| E400h-E5FFh | 1 | 1 | 1 | 0 | 0 | 1 | 0 | X | X | X | X | X | X | X | X | X | |
| FCC0h-FCDFh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | X | X | X | X | X | |
| FEA0h-FEAFh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 1 | 0 | X | X | X | X | |
| FF90h-FF97h | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | X | X | X | X | |
| 8 | 3800h-3FFFh | 0 | 0 | 1 | 1 | 1 | X | X | X | X | X | X | X | X | X | X | X |
| AC00h-AFFFh | 1 | 0 | 1 | 0 | 1 | 1 | X | X | X | X | X | X | X | X | X | X | |
| E600h-E7FFh | 1 | 1 | 1 | 0 | 0 | 1 | 1 | X | X | X | X | X | X | X | X | X | |
| FCEOh-FCFFh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | X | X | X | X | X | |
| FEB0h-FEBFh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | X | X | X | X | |
| FF98h-FF9Fh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | X | X | X | X | |
| 9 | 4000h-47FFh | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | X |
| B000h-B3FFh | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | |
| E800h-E9FFh | 1 | 1 | 1 | 0 | 1 | 0 | 0 | X | X | X | X | X | X | X | X | X | |
| FD00h-FD1Fh | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | X | X | X | X | X | |
| FEC0h-FECFh | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | X | X | X | X | |
| FFA0h-FFA7h | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | X | X | X | X | |
Прошивка ПЛМ 2